Abstract : This interim response action consists of the design and construction of improvements to the North boundary containment system. The purpose of this document is to outline the main elements developed in the preliminary design phase of the IRA. The following elements of the IRA are discussed: (1) Recharge trenches. (2) Well closure. (3) Design flow rate. (4) Existing ground water treatment process. (5) Treatment system modifications. (6) Additional carbon storage. (7) Building modifications. (8) Treatment plant operational improvements.